1. Field
The present invention relates generally to using a Captcha having visual information related to a source of the Captcha.
2. Background
A Captcha (also referred to as CAPTCHA—Completely Automated Public Turing test to tell Computers and Humans Apart) is a challenge and response test which ensures that the response to a challenge is from a human user instead of from a computer. A Captcha is designed so that it is relatively easy for a human user to recognize distorted characters of the challenge, but it is very hard for pattern recognition software to extract and recognize the distorted characters. Captchas have been widely used in servers to frustrate automated traffic.
A Captcha may be subject to a type of relay attack. To launch a relay attack, a hacker sets up a website which interests many innocent users using either legal or illegal content. Whenever the hacker needs to return a Captcha response to, for example, XYZ Bank, the hacker forwards the Captcha challenge received from a server for the XYZ Bank to an innocent user of hacker's website, which website, of course, is not associated with the XYZ Bank. Not knowing the source of the Captcha, the innocent user may respond to the Captcha challenge, and may be unwittingly involved in the hacker's online fraud.
There is therefore a need for a technique for providing Captcha source information to a user in a manner that may allow a user to avoid unwittingly being involved in online fraud.